1. Field of the Invention
The present invention relates to an open-end wrench and, in particular, to an open-end wrench including a ratchet mechanism.
2. Description of the Related Art
U.S. Pat. No. 2,700,315, entitled open-end ratchet wrench, shows a wrench including a head with a slot. Two dogs are respectively disposed at two sides of the slot. Each dog is pivotally engaged in a recess with a pivot and is pivotal relative to the head. Each dog is subject to a biasing force of a spring, which facilitates the dog to return to its original position. A shaft is used to fix each spring. However, each dog does not have a strong structure, because it is made with a through hole for pivot. A larger shear force can cause the pivot to break, because the pivot is limited to have a relatively small cross-sectional area. Therefore, the ratchet wrench can't withstand a large torque transmission well. The present invention is, therefore, intended to obviate or at least alleviate the problems encountered in the prior art, as well as to make a simple and cost-saving wrench.